R1:77a876582483

Schema patch to add a column to Phabricator_File.file table

Summary: Added a column called explicit_upload to Phabricator_File.file table

Test Plan: By chekcing locally if the the column has been added in table using mysql commands.

Reviewers: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5384